The effect of intravenous lidocaine on experimental brain edema and neural activities.

A series of experiments was conducted to clarify the effect of intravenous administration of lidocaine on brain water content, local cerebral blood flow (lCBF), and neural recovery in brain injury induced by exposure of the cat's cerebral surface to the air. The injury produced ischemia and edema in the cortex and white matter without direct damage of the cortex. Lidocaine (3.0 mg/kg) was given intravenously for 30 minutes immediately after air exposure and thereafter at the rate of 2 mg/kg/hour. Twelve hours after exposure, lidocaine significantly suppressed cortical ischemia and edema; however, it had no effects in the white matter. The electrophysiologic activities of the cortex and white matter which were assessed by the direct cortical response and somatosensory evoked response were significantly preserved by lidocaine compared with nontreated animals. The results of this experiment demonstrate that intravenous lidocaine has a significant beneficial effect on cortical ischemia and electrophysiologic activities of the cortex and white matter in injured brain.